From: Wolfgang Bangerth <bangerth@colostate.edu>
Date: Tue, 4 Oct 2022 17:51:13 +0000 (-0600)
Subject: Guard running doxygen in parallel with a version check.
X-Git-Tag: v9.5.0-rc1~907^2
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F14335%2Fhead;p=dealii.git

Guard running doxygen in parallel with a version check.
---

diff --git a/doc/doxygen/CMakeLists.txt b/doc/doxygen/CMakeLists.txt
index ed4655130e..29c082e97f 100644
--- a/doc/doxygen/CMakeLists.txt
+++ b/doc/doxygen/CMakeLists.txt
@@ -34,6 +34,7 @@ IF(NOT DOXYGEN_FOUND)
     )
 ENDIF()
 
+
 ########################################################################
 #
 # Process the tutorial and code-gallery files into inputs for doxygen
@@ -272,6 +273,19 @@ FILE(APPEND "${CMAKE_CURRENT_BINARY_DIR}/options.dox"
   "
   )
 
+# If we use a reasonably modern doxygen version, make sure it is run in parallel
+IF(NOT (${DOXYGEN_VERSION} VERSION_LESS 1.9))
+  FILE(APPEND "${CMAKE_CURRENT_BINARY_DIR}/options.dox"
+    "
+    NUM_PROC_THREADS       = 0
+    DOT_NUM_THREADS        = 0
+    "
+    )
+  MESSAGE(STATUS "Letting doxygen run with multiple threads")
+ENDIF()
+
+
+
 ########################################################################
 #
 # And, finally, call doxygen:
diff --git a/doc/doxygen/options.dox.in b/doc/doxygen/options.dox.in
index c4e6e00744..9e0271628e 100644
--- a/doc/doxygen/options.dox.in
+++ b/doc/doxygen/options.dox.in
@@ -77,7 +77,6 @@ EXAMPLE_RECURSIVE      = NO
 IMAGE_PATH             =
 INPUT_FILTER           = ${CMAKE_SOURCE_DIR}/doc/doxygen/scripts/filter.pl
 FILTER_SOURCE_FILES    = YES
-NUM_PROC_THREADS       = 0
 
 # Have some user defined commands that we can use in the documentation
 # and that expands to specific text. For some more transformations, see
@@ -291,7 +290,6 @@ DOT_TRANSPARENT        = NO
 GENERATE_LEGEND        = YES
 
 DOT_CLEANUP            = YES
-DOT_NUM_THREADS        = 0
 
 #---------------------------------------------------------------------------
 # Configuration::additions related to the search engine